Ultrasonic-thermostatic-assisted cloud point extraction coupled to high-performance liquid chromatography for the analysis of adrenalines residues in milk

A novel approach, ultrasonic-thermostatic-assisted cloud point extraction (US-CPE) combined with high-performance liquid chromatography and ultraviolet detection, is developed for the analysis of adrenalines (beclometasone dipropionate, hydrocortisone butyrate and nandrolone phenylpropionate) in milk samples. It is based on the induction of micellar organized medium by using a non-ionic surfactant TMN-6 (polyether-type organic silicon surfactant; structure: (CH3)3C(CH2)8(OC2H4)XOH; average of X = 6) to extract the target adrenalines. In this experiment, phase diagrams were used to study the cavitation and mass transfer behaviors of the two phases on micelles of TMN-6. The main advantages of this system were that it had no ultraviolet absorption and had higher extraction efficiency. In addition, the phase diagram of US-CPE was determined contrast with ultrasonic-thermostatic-cloud point system. The effects of other operating parameters, e.g., concentration of salt and centrifugation time on extraction of US-CPE system, have also been studied in detail.